1. Field of Invention
The present invention pertains to a low noise blockdown converter capable of accepting input of one or more signals received by means of one or more substantially parabolic antennas, capable of carrying out frequency conversion on at least one of the received signal or signals, and capable of sending at least one signal produced as a result of this frequency conversion to one or more receivers.
2. Conventional Art
A low noise blockdown converter (hereinafter also referred to as “LNB”) of this type, being attached to a feeder horn of a parabolic antenna for use in receiving satellite broadcasts, accepts input of a received signal gathered by the parabolic antenna and guided thereto by the feeder horn. Moreover, this received signal is subjected to frequency conversion, and the signal produced as a result of frequency conversion is sent to a receiver by way of coaxial cable. If, for example, a received signal of several GHz is input thereto, this received signal might be converted to a signal of several MHz which is then sent therefrom.
Furthermore, a high-performance LNB might have microcomputer(s) installed therein. LNB 101 shown in FIG. 9 may have a single microcomputer 104 installed therein, connection of microcomputer 104 to respective receiver(s) 103 being permitted by way of I/O port(s) 102.
Here, the maximum number of I/O ports 102 which microcomputer 104 is capable of accommodating might for example be defined in advance to be two. Accordingly, an LNB 111 having a single I/O port 102 such as that shown in FIG. 10 would have a single microcomputer 104 installed therein. Furthermore, an LNB 121 having four I/O ports 102 such as that shown in FIG. 11 would require that two microcomputers 104 be installed therein. Moreover, if the number of I/O ports 102 is increased, it will be necessary to increase the number of microcomputers 104.
Responsive, for example, to inquiry or inquiries from receiver(s), such LNB microcomputer(s) might return, from I/O port(s) to receiver(s), information specific to the LNB. LNB-specific information might include the serial number of the LNB in question, which might be used for customer support purposes.
Furthermore, where a plurality of microcomputers are installed in the same LNB, it will be necessary for the microcomputers to share information specific to the LNB. Specific information which is identical in content has therefore conventionally been stored in each of a number of microcomputers which have then been installed in the same LNB.
However, where a plurality of microcomputers in which specific information that is identical in content has been stored are to be installed in the same LNB in accordance with the conventional art as described above, it has been necessary to manage the microcomputers as a single set, which has complicated parts control. Alternatively it is sometimes the case that a plurality of microcomputers storing sets of specific information that are respectively different in content are accidentally installed in the same LNB, which fact has resulted in a defective LNB.
Furthermore, separate special-purpose microcomputers might be developed to accommodate each of the several possible numbers of LNB I/O ports, making it possible for a single microcomputer to be installed in a single LNB no matter how many LNB I/O ports there are and eliminating the possibility that any one LNB could receive a plurality of sets of specific information that are mutually different in content. However, in such a case, the increase in the number of types of microcomputers would complicate parts control and would lead to increased microcomputer cost.